Wear-resisting body and method of making the same.



G. DANTSIZEN.

WEAR RESISTING BODY AND METHOD OF MAKING THE SAME.

APPLICATION FILED FEB. s, 1912.

1,096,688. Pat nted May12,191 l Fig.3.

WITNESSES JN YENTUH HI S ATTUHZYEY.

sequent to filing;

UNITED STATES PATENT OFFICE.

CHRISTIAN DAN'TSIZEN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL,ELEOTRIC COMPANY, A CORPORATION OF NEW YORK.

WEAR-RESISTING BODY AND METHOD OF MAKING THE SAME.

Specification of Letters Patent.

Patented May 12, 1914.

Application filed February 6, 1912. Serial No. 675,829.

To all w/mmc't may 0022 m:

Be it known that I, CHRISTIAN DANTSIZEN, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Wear-Resisting Bodiesand Methods of Making the Same, of which the following is aspecification.

My present invention comprises a material consisting of refractoryearthy oxids such as the oxids of aluminum, beryllium, and titanium, ina very hard dense condition' free from crystalline structure andtherefore especially valuable as a Wear-resisting body such as a die, Ihave discovered that these oxids, particularly alumina, Al. ,O can besintered to a very dense state without actual fusion and consequentcrystallization. The material is mechanically strong and far moredurable than steel for the purposes mentioned. It is as hard as sapphireand possesses some of the desirable wearing quahties of diamond.

In the accompanyin drawings Figure 1 shows a preliminary form into whichthe material is shaped when it is intended to utilize it for a die; Fig.2 shows the material after havin been trimmed in a lathe sub- Fig. 3shows the finished die with its mount, and Fig. 4 shows the die andmount assembled in final form.

I will describe in its various stages the manufacture of a die from theloose oxid powder to the mounted die, referring in this descriptionparticularly to aluminum-oxid. I wish it understood that thisdescription is also illustrative of other forms of tools, rolls,bearings, drills and the like.

Very finely divided aluminum oxid is mixed with about 10% of suitablebinder such as gum tragacanth. When it is de sired to make a die forwire drawing the mixture is compressed into the form of a fiat cylinderwhich may be for example, one' fourth inch high and three-fourth inch indiameter. C linders or die blanks such as these are ba ed in an ordinarykiln at a temperature of about 1300 to 1400 C. After baking thesubstance has the consistency of chalk and therefore may be easilymachined. The depression in the top of the die blank shown in Fig. 1 isincreased along its axis so as to extend through the cylinder as shownin Fig. 2. When thus bored the cylindersare fired to 1800 to 2000 C.

or metal working tool:

in an inert environment.

A furnace suitable I for carrying out the firing operations is foralumina but it is a higher temperature than has been heretofore used tobake or fire alumina. I find it sinters the alumina into a very dense,amorphous or structureless condition in which it is very strong, finegrained and is hard as sapphire. This form of alumina is not to beconfused with the commercial article known as alundum. The lattersubstance is an impure form of alumina which has been electricallymelted and has a crystalline structure. When alundum is heated andplunged into water it cracks into pieces. Hig produced according to theabove process may be heated to 1000 C. or even higher, and then may beplunged into water without dama e. In order to identify it from theslight y baked alumina heretofore'produced I may say it has a specificgravity of 3.8 to 3.9. It 1s capable of taking a high polish withdiamond dust. It is opaque.

After having been fired as above described the dies are given theirproper shape with. diamond dust and are then mounted in a casingillustrated in Fig. 3, the die 2 placed in a recess prepared for it inthe steel or 11y sintered alumina brass casing 1 and the plate 3 isinserted into a recess in the holder 1 which is somewhat under-cut asshown in the drawing. The plate 3 is then upset by pressure so as toedge of the holder is then spun over the edge of the plate 3 to hold itin place as shown in Fig. 4.

For the drawing of copper, a die made as above described lasts sixtytimes as long as the ordinary steel die. Of course, metals other thancopper, such as steel, nickel, or even tungsten may be drawn both coldand hot through my improved 'die.

When making articles of oxids other than aluminum oxid, the process isessentially the same, except that the final firing temperature should inall cases be below the melting point of the respective material.

I mean by the appended claimsto cover not only an article consisting ofthe oxid of aluminum but also of the described equivaflow into theundercut portion and-the ,ing pf an oxid of lents, namely, the oxids ofberyllium andv titanium.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. An article of manufacture consisting of aluminum oxid sintered in itsapproxi mate shape ata temperature just below its melting point to adense, amorphous state in which 1t is capable of taking a high polishand withstanding sudden changes of temperature without cracking. I

body consist- 2. A' shaped wear-resisting aluminum sintered in itsapproximate shape to a strong, hard, structureless form capableof takinga high polish.

I ing of dense, opaque,-oxid of aluminum sintakes place, shaping thetered in its approximate shape devoid of crystalline structure andhaving a specific gravity of 3.8 to 3.9, and a hardness equal -to thatof sapphire.

4.- The process which consists in com-pacting a refractory oxid with abinder, baking to a temperature at which slight sintering materialmechanically and finally firing at a higher tempera-' ture below themelting'point at which complete sintering takes place.

' 3. A shaped wear-resisting body consist-- ture of about 1300 0.,machining1 the material to its approximate final s ape and then firingto a higher temperature just below the melting point of the oxid wherebysintering to a dense, strong, structureless state is secured.

'7. The process which consists in compact:

ing aluminum oxid and gum tragacanth, baking toslightlysinter thematerial, shaping the same into desired form, and firing t a temperatureof about 1800 to 2000 C. to sinter the' same into a dense, amorphousstate.

In witness whereof, I have hereunto set my hand this 5th day ofFebruary, 1912.

CHRISTIAN DANTSIZEN.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

